// Copyright (c) 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_BASE_X_X11_MENU_LIST_H_
#define UI_BASE_X_X11_MENU_LIST_H_

#include <vector>

#include "base/macros.h"
#include "ui/base/ui_base_export.h"
#include "ui/gfx/x/x11_types.h"

// A process wide singleton cache for X menus.
namespace base {
template <typename T>
struct DefaultSingletonTraits;
}

namespace ui {

// Keeps track of created and destroyed top level menu windows.
class UI_BASE_EXPORT XMenuList {
public:
    static XMenuList* GetInstance();

    // Checks if |menu| has _NET_WM_WINDOW_TYPE property set to
    // "_NET_WM_WINDOW_TYPE_MENU" atom and if so caches it.
    void MaybeRegisterMenu(XID menu);

    // Finds |menu| in cache and if found removes it.
    void MaybeUnregisterMenu(XID menu);

    // Inserts cached menu XIDs at the beginning of |stack|.
    void InsertMenuWindowXIDs(std::vector<XID>* stack);

private:
    friend struct base::DefaultSingletonTraits<XMenuList>;
    XMenuList();
    ~XMenuList();

    std::vector<XID> menus_;
    XAtom menu_type_atom_;
    DISALLOW_COPY_AND_ASSIGN(XMenuList);
};

} // namespace ui

#endif // UI_BASE_X_X11_MENU_LIST_H_
